Lab Notes 01 – August 20th, 2015

Who am I?

I’m Chris. I love nature. I love hiking in the mountains and the desert. The ocean. Lakes. Grasslands. I’ve enjoyed seeing the variety that the worlds’ geography has to offer. When you think about the variety of climates the world hosts, the fact that plants have evolved the ability to thrive virtually everywhere is incredible.

I’ve always wondered: “How do they do that? How do plants actually work?” It started when I worked on a golf course on the east coast where I watched teams of hard working laborers spot-shower grasses with water to cool rootzones and leaf tissue in peak summer heat. I learned that some grasses needed this treatment more than others. When you consider the annual water use for purposes like this across the United States alone the scope of water use in America begins to come to light.

So I began to acquire the academic training I would need to answer these questions about plants, and more importantly: crops. I completed my undergraduate training at Rutgers University in New Jersey where I worked with the turfgrass and crop stress physiologist Bingru Huang. I soon realized the critical role that water use and management has in governing grasses’ growth. Wanting to dig deeper at a mechanistic level, I enrolled in a graduate program at Utah State University. Here in the Intermountain West, I was exposed to frontline strategies of dealing with chronic and acute drought. There, I observed the impact of wheat bred for the high deserts of UT, CO, WY, NV and ID. I studied the effects of turfgrasses and trees grown adjacent to one another, and observed first-hand the impact of plants’ gene-encoded drought-avoidance strategies.

 

Figure 1. United States drought monitor for California from August 11, 2015. “Exceptional” or “Extreme” drought dominates much of the Sacramento and San Joaquin Valley agricultural regions. Image courtesy http://droughtmonitor.unl.edu/data/pdfs/20150811/20150811_CA_trd.pdf

But I wanted to dig even deeper. I wanted to explore the critical interface between plants and their environment: the genetic and molecular levels. I soon began my Ph.D. program in the Department of Horticulture at Washington State University. Here I found an exciting region strongly impacted by the health of its agricultural industry and natural resource management. I studied the utilization of pear fruits’ genes during their unique ripening processes under the guidance of Amit Dhingra, now a leading scientist in agricultural genomics. Here I observed that crops’ water use impacts individual, community and regional health from medical to economic contexts. My training during my time at WSU (Go Cougs!) allowed me to begin answering these challenges in innovative ways.

 

Figure 2. 2013 United States drought monitor of California, with dominant counties of production and percentage of American market (for each commodity). Note significant growth of “Exceptional” drought region in 2015 image, relative to this one. Image modified from http://www.motherjones.com/files/Final-Crop-Map_1.gif

What motivated this project?

The need for food is drought-proof. It’s heat-proof. It’s recession-proof. An expanding population will always need more food. Climate change threatens global farmland, yielding to deserts. This can be seen throughout the American southwest and other areas with populations that rely on irrigated farmland. This is also seen abroad in shrinking freshwater lakes of sub-Saharan Africa, where climate change and large-scale irrigated agriculture (Figure 3) persist. This is a global concern, and it’s only beginning. Innovative solutions are needed to address these problems. It doesn’t take a plant scientist to appreciate plentiful food and unspoiled nature. We need to feed the world without sucking it dry. Instead of developing new crops that eke out a bit more yield under current or near-current watering regimes, we need to be able to get any yield out of much more land.

 

Figure 3

Fortunately, native species can provides the biology needed for sustained agriculture. Enter a remarkable genus of grasses that are genetically similar to the major grains of the world: Sporobolus. Sporobolus contains over 150 species, and is found from tundra to blazing deserts. Within it is a ‘resurrection grass’ (Sporobolus stapfianus)

 

Figure 4. (top left) Sporobolus nealleyi thriving on a gypsum crusted soil in the New Mexico desert. (bottom left) Sporobolus cryptandrus. Remarkable drought and salt tolerance. Images courtesy http://swbiodiversity.org. (right) Apperance of gypsum erosion adjacent to rootzone of another gypsophile (Palacio et al., 2014. Nature Communications). Could this be a clue at the mode of action of gypsum-endemism in plants?

Recently, another gypsophile native to the Spanish semi-arid deserts was reported to preferentially acquire crystallized, tightly-bound water from pure mineral gypsum rock in lower strata of its rootzone during times of drought. This presents the exciting possibility that S. nealleyi (another gypsophile) may exhibit the same behavior. If this mechanism is shared between species, and can be identified- it may be exploited numerous breeding and biotechnological approaches to dramatically improve cereal crops’ drought tolerance. To be clear: we’re talking about crops getting water from rocks. This has tremendous potential. A long term goal of the work would be to begin testing the function of candidate gypsum-endemism genes in corn, rice and wheat to determine if similar drought tolerance is achieved. Of course, none of this is possible without getting a look under the hood of this remarkable grass. The research community needs a robust Sporobolus nealleyi genome to begin on the path towards realizing these goals.

I am thrilled to begin working on this project. I’m planning site visits to the greater Albuquerque area to collect some live specimens during the end of August or beginning of September, thanks to the kind assistance of Tim Lowrey (University of New Mexico). My first objective is to get an estimate of S. nealleyi genome size. I’ll be shipping some of my fresh tissue samples up to a service lab up in Seattle that will help me with this critical task! From there, I can begin to see what kind of a genome assembly can be generated.

Exciting times ahead